Polymers of carbon monoxide and olefinically unsaturated organic compounds, or polyketones, have been known and available in limited quantities for many years. For example, polymers of ethylene or ethylene-propylene which contain small quantities of carbon monoxide are disclosed in U.S. Pat. No. 2,495,286, prepared using free radical catalysts. British Patent No. 1,081,304 discloses polymers containing higher concentrations of carbon monoxide prepared using alkylphosphine complexes of palladium salts as catalysts. U.S. Pat. No. 3,948,873 issued to Hudgin, discloses a method of preparing ethylene-carbon monoxide copolymers using organic peroxide catalysts. The method involves polymerization of the monomers in the presence of a small amount of potassium dihydrogen phosphate.
U.S. Pat. No. 4,143,096 issued to Hudgin discloses graft interpolymers comprised of a polyolefin backbone polymer prepared from at least one alpha-olefin of two to four carbon atoms onto which is graft a copolymerized mixture of ethylene and carbon monoxide.
A special class of linear polyketones is disclosed in U.S. Pat. No. 3,694,412, wherein the monomer units of carbon monoxide and olefinically unsaturated hydrocarbons occur in alternating order.
Polyketones are of considerable interest because they exhibit good physical properties. In particular, the high molecular weight linear alternating polymers have potential use as engineering thermoplastic due to their high strength, rigidity and impact resistance. These polymers can be represented by the general formula ##STR1## wherein A is the moiety obtained by polymerization of the olefinically unsaturated organic compound through the olefinic unsaturation. A general process for preparing such linear alternating polymers is disclosed, for example, in published European Patent Application 121,965 and 181,014. The process generally comprises contacting the monomers in the presence of a catalyst obtained from a compound of palladium, cobalt or nickel, the anion of a non-hydrohalogenic acid having a pKa less than about 2, and a bidentate ligand of phosphorus, arsenic or antimony. The resulting linear alternating polymers are generally high molecular weight thermoplastic polymers having utility in the production of articles for food and drink containers and for automobile parts.
Although the properties of the polyketones are suitable for many applications, it would be of advantage to provide polyketone compositions which exhibit less mold shrinkage and certain mechanical properties that are improved over the corresponding properties of the polymer alone.